Seasonal Microbial Population Shifts in a Bioremediation System Treating Metal and Sulfate-Rich Seepage

Abstract

Biochemical reactors (BCRs) using complex organics for bioremediation of mine-influenced water must operate successfully year round. In cold climates, where many mines in Canada are located, survival of the important microorganisms through the winter months is a concern. In this work, broad phylogenetic surveys, using metagenomics, of the microbial populations in pulp mill biosolids used to remediate metal leachate containing As, Zn, Cd and sulfate were performed to see if the types of microorganisms present changed over the seasons of one year (August 2008 to July 2009). Despite temperature variations between 0 and 17˝C the overall structure of the microbial population was fairly consistent. A cyclical pattern in relative abundance was detected in certain taxa. These included fermenter-related groups, which were out of phase with other taxa such as Desulfobulbus that represented potential consumers of fermentation byproducts. Sulfate-reducers in the BCR biosolids were closely related to psychrotolerant species. Temperature was not a factor that shaped the microbial population structure within the BCR biosolids. Kinetics of organic matter degradation by these microbes and the rate of supply of organic carbon to sulfate-reducers would likely affect the metal removal rates at different temperatures.

High-Throughput Recovery and Characterization of Metagenome-Derived Glycoside Hydrolase-Containing Clones as a Resource for Biocatalyst Development

“…The redundant clones were most prevalent in the FOS62 and TolDC libraries (37 and 10 redundant clones, respectively), while there were no clones meeting the redundancy criteria identified within any of the soil libraries. This is consistent with the observed alpha diversity for bioreactor and soil milieus, with the highest diversity represented in organic and mineral soil horizons (22, 26, 27).…”

Hydraulic retention time and pH affect the performance and microbial communities of passive bioreactors for treatment of acid mine drainage

“…were also identified (approximately 2% of the total; data not shown). Low relative abundances of SRB species were observed previously in a passive bioreactor (Baldwin et al 2016 ). At a 5 h HRT (unstable operation), the relative abundance of OTU 58670 increased to account for 11.9% of the total.…”

“…In a sulfate-reducing bioreactor, the seasonal changes in SRB species can be monitored by pyrosequencing (Baldwin et al 2016); however, little is known about the responses of microbial communities other than SRB to changing conditions during the treatment of AMD. Using a combination of chemical analyses and Illumina sequencing of 16S rRNA genes, the relationship between reactor performance and microbial community structure during operation of the JOGMEC process were analyzed.…”

“…As for microbial community analysis, the recent development of high-throughput DNA sequencing technologies has enabled analysis of complicated microbial communities in natural environments at high resolution and with high sensitivity (Hori et al 2014 , 2015 ; Sato et al 2016 ). In a sulfate-reducing bioreactor, the seasonal changes in SRB species can be monitored by pyrosequencing (Baldwin et al 2016 ); however, little is known about the responses of microbial communities other than SRB to changing conditions during the treatment of AMD. Using a combination of chemical analyses and Illumina sequencing of 16S rRNA genes, the relationship between reactor performance and microbial community structure during operation of the JOGMEC process were analyzed.…”

Simultaneous Biological and Chemical Removal of Sulfate and Fe(II)EDTA-NO in Anaerobic Conditions and Regulation of Sulfate Reduction Products

“…Abundance reached 22.53%, 0.7%, 1.05%, 2.81% and 1.15%, respectively (Figure 4). These five bacteria can use organic carbon sources such as sodium lactate to reduce sulfate [48][49][50][51] and the dominant strain was Desulfomicrobium. A sulfur autotrophic denitrifying bacteria Sulfurovum was also found in the system, accounting for 1.39%.…”